Advanced control of liquid water region in diffusion media of polymer electrolyte fuel cells through a dimensionless number

JOURNAL OF POWER SOURCES

卷:315

Article

Wang, Yun^1,2  Chen, Ken S.³ 

[1] Univ Calif Irvine, RERL, Irvine, CA 92697 USA

[2] Univ Calif Irvine, Dept Mech & Aerosp Engn, Natl Fuel Cell Res Ctr, Irvine, CA 92697 USA

[3] Sandia Natl Labs, Livermore, CA 94550 USA

关键词: Polymer electrolyte fuel cells;    Phase change;    Non-isothermal;    Liquid water region;    Dimensionless number;   

DOI  :  10.1016/j.jpowsour.2016.03.045

来源: Elsevier

【 摘 要 】

In the present work, a three-dimension (3-D) model of polymer electrolyte fuel cells (PEFCs) is employed to investigate the complex, non-isothermal, two-phase flow in the gas diffusion layer (GDL). Phase change in gas flow channels is explained, and a simplified approach accounting for phase change is incorporated into the fuel cell model. It is found that the liquid water contours in the GDL are similar along flow channels when the channels are subject to two-phase flow. Analysis is performed on a dimensionless parameter Da(0) introduced in our previous paper [Y. Wang and K. S. Chen, Chemical Engineering Science 66 (2011) 3557-3567] and the parameter is further evaluated in a realistic fuel cell. We found that the GDL's liquid water (or liquid-free) region is determined by the Da(0) number which lumps several parameters, including the thermal conductivity and operating temperature. By adjusting these factors, a liquid-free GDL zone can be created even though the channel stream is two-phase flow. Such a liquid-free zone is adjacent to the two-phase region, benefiting local water management, namely avoiding both severe flooding and dryness. Published by Elsevier B.V.

【 授权许可】

Free